


Who's Little Brother

by J000liet



Series: This Is Why We Can't Have Nice Things [12]
Category: Haikyuu!!
Genre: F/M, Trading Sibilings
Language: English
Status: Completed
Published: 2017-08-13
Updated: 2017-08-13
Packaged: 2018-12-14 18:21:25
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 1,991
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11788809
Author URL: https://archiveofourown.org/users/J000liet/pseuds/J000liet
Summary: When eldest sibilings come out as a couple, the only way to get the little brothers to see eye to eye is to trade.And Tsukishimas and Tanakas go about as well together as oil and water.





	1. The Set Up

Tanaka came home to his sister singing. That was not normal.

That same day, Tsukishima came home and his brother was whistling and smiling and  _ hugging  _ him… He just went to his room.

...0...0...0...

“So what are we going to tell them?” Saeko nuzzled into his chest.

“We’ll think of something.” He sighed and kissed the top of her head.

...0...0...0...

“Hey… Tsuki?” Akiteru knocked on his little brother’s door. 

“What.”

“Can I talk to you?” Akiteru opened the door.

“What.”

“I met a girl.”

“Oh.”

“She’s really nice and sweet and she seems a bit rough around the edges, but she’s so smart and amazing-”

“I get it. You like her.” Tsukishima sighed. “What’s her name?”

“Saeko.”

“Sae...ko…”

“Mmm.”

“As in..  _ Tanaka _ Saeko.” Tsukishima growled.

“Yeah.” Akiteru sighed with a smile on his face.

“YOUR DATING TANAKA’S SISTER!?” Tsukishima yelled.

...0...0...0...

“Hey, baby bro?” Saeko looked at him over the table.

“Yeah?” Tanaka shoved food into his mouth.

“I started dating a guy.”

“What!?” Tanaka spit his food out. “Is he a good guy?”

“Yeah.” Saeko nodded. “He’s sweet and loving and he’s going to college and played volleyball and he’s not afraid to tease or play pranks. He’s a good boy.” She giggled. “And I think I love him.”

“Wha-” Tanaka just eyed her. “What’s his name?”

“Akiteru.” She smiled.

Tanaka squinted. “Akiteru? I know an Akiteru…”

“You should.” She smiled.

“It is the same one?”

She just nodded happily.

“You’re dating a  _ TSUKISHIMA?” _

...0...0...0...

“HEY! TSUKISHIMA! I HAVE A BONE TO PICK WITH YOU!” Tanaka stormed into the gym.

“Well, well, well. What a coincidence. I have a bone to pick with  _ you _ .” Tsukishima stood from his stretches.

“Whats going on?” Hinata eyed Yamaguchi.

“Apparently-”

“WHY is  _ YOUR _ brother dating  _ MY  _ sister!” Tanaka yelled and everyone froze.

“That.” Yamaguchi sighed.

“Coincidentally, I have the same question. Why does my brother even know your sister exists?”

“Boys…” Ukai warned.

“What was that?” Tanaka growled.

“All I’m saying, is that your sister and my brother have never met before. How does she even know she exists?”

“Boys.” Ukai went over to them.

“She told me that volleyball was involved. What’s up with that?” Tanaka got up in Tsukishima’s face.

“Well he told me that she was smart. What school did she go to?” Tsukishima replied.

“BOYS!” Ukai pushed them apart. “That’s enough. Cool down the both of you.”

“He started it!” They pointed at each other.

Ukai just sighed. “Listen. Your siblings are adults. They can date whoever they want.”

“NOT HIM!” They yelled again.

“Um… is this a bad time?”

“Akiteru.” Tsukishima crossed his arms and sighed. 

“Hey. I thought there would be an issue today… Saeko called me.” He rubbed his neck. “Said things didn’t really go too well last night.”

“I remember you in middle school.” Ukai eyed the shorted Tsukishima. “You were good.”

“Thanks.” Akiteru blushed.

“Is it safe?” Saeko put her head through the door. 

“Sis!” Noya ran over. “Is it true you’re dating Tsukishima’s older brother!?”

“Yeah…”  She stepped into the gym before walking over to the two boys in question.

“Okay!” Suga stepped in, sensing the tension. “I have an idea.”

“What would that be?” Akiteru wrapped an arm around Saeko (who blushed uncharacteristically).

“Switch siblings for a day.”

Four sets of terrified eyes looked at him.


	2. The Boys

**Summary for the Chapter:**

> Tanaka and Akiteru have more in common than just a girl.

* * *

 

“So… what does Tanaka like to do?” Akiteru asked his brother.

He was just ignored.

 

“What does your brother like to do?” He asked Saeko.

“Volleyball and eat.” She laughed and kissed him on the temple. “Have fun the day after tomorrow.”

He sighed.

 

“Hey, Yamaguchi. What would Tanaka like to do?” He asked over the phone.

“Sports. Food. His sister. Girls in general. Ooo! He likes the beach.”

“Thanks.”

“No problem.” Yamaguchi chirped over the phone. “You owe me.”

* * *

He was being eyed like he was a parasite.

“Hello…” He waved to the younger Tanaka.

“What?” Tanaka spit.

“I thought we would go to the beach today.”

“Beach?”

“Yeah.” Akiteru nodded.

“Why?”

“Surprise.” Akiteru smirked. 

They got into his car and started to head on the long drive to the beach. He turned on the radio and Pink Floyd came on over the radio.

“Rock?” Tanaka eyed him.

Akiteru just laughed. “Surprised?”

“You’re just so…”

“What?”

“Clean.” 

Akiteru let out a single bark.

“What?”

“You really have no idea do you?”

“My sister called you a good boy.” Tanaka eyed the older.

“I can drink your sister under the table, and I didn’t get that from being a good boy.”

“ _ You _ can out drink  _ my  _ sister?” Tanaka gasped.

“Yeah. She can out do me on a lot of things too. Like,” he laughed a little, “I will  _ never _ let her drive my car. She can out do me on any race every single time.” Tanaka joined him on a laugh. “And I will never be able to drive a motorcycle. And I have no pain tolerance.” He laughed. “I stub my toe and cry.”

“Whimp.”

“Yep.”

“At least you admit it.” Tanaka settled into his seat. “What are you studying?”

“Psychology and mathematics.”

“What are your doing with that?”

“I think I want to teach.” He smiled. “Maybe go into sports management. I have some more time to decide if I want to do some anatomy classes.”

They sat in silence almost the rest of the way. 

“Hey Ai!” He called out to his friend on the beach.

“Tsuki!” She waved back.

“Do I need to be worried?” Tanaka eyed Ai.

“She’s lesbian.” Akiteru smiled. “And gets along great with Saeko. Can’t control the two of them together.”

They met her at the beach.

“So what are we doing here?”

“Ai is going to teach you how to surf.” Akiteru smiled. 

Tanaka eyed her, then Akiteru, then just screamed.

“He okay?” Ai giggled.

“I don’t know.” Akiteru shrugged.

...0...0...0...

Tanaka walked into his house, tired and happy.

“Was it good?” Saeko looked over the sofa.

“It was amazing!” He smiled.

“What did you do?”

“We went surfing.” He collapsed next to her.

“So you met Ai.” She giggled.

“She’s hilarious.” 

“Yeah.”

“And I guess… Tsukishima the first is not too bad.”

“Ya like him!” Saeko cheered.

“I… I guess.” He sighed.

“Good.” She smiled.

“But-”

“Oh no.” Saeko eyed her brother.

“Can he really out drink you?”

She cackled. “Yup.”

“No one can do that.”

“He can.” She nodded. “That’s the day I asked him out. I didn’t remember, and he came to collect and I just said yes so he wouldn’t figure it out. Don’t tell him?”

“Kay.” He smiled.

“What?”

“It’s nice to see you happy.”

“I am happy.” She nodded.

“Good.”

* * *

 


	3. The Blondes

**Summary for the Chapter:**

> The blondes spend some time together.

* * *

 

“Hey, baby bro, what does Akiteru’s little brother like to do?”

“I dunno. He’s kinda a wet blanket… i guess.”

 

“Hey, Aki?” She sipped her milkshake.

“Yeah?” He dipped a fry in her shake.

“What does your brother like?”

“Strawberries and dinosaurs.” Akiteru laugh. “He’s a calm person. He doesn’t do hot blood, i guess.”

“Oh boy…” she sighed and took another sip of her milkshake.

* * *

Saeko took a deep breath as she picked up Akiteru’s younger brother. She had edited her earrings to be a bit calmer, she was wearing one of her few pairs of unripped jeans and a shirt with a tank that had a stylized rabbit and ‘Ferocious Vegan’ written on it and her nice leather jacket. She hoped it was cool-blooded enough.

“So what are we doing and how can it be gotten over fastest?” Tsukishima came out of the house.

“Museum in town.” She smiled. “And don’t worry, you don’t have to ride my bike.”

Tsukishima just eyed her.

“I’m not gonna kill my beau’s younger brother. I’m not stupid.”

“So why didn’t you go to college?”

“I did.” She smiled.

“What?”

“I was studying linguistics.” She smiled. “I went for a year and a half.”

“Then why did you stop?”

“Me and Ryuu…” she sighed, “our dad got sick. So I came back to take over the shop.”

“What shop?”

“Florist.”

“I can’t see you as a florist.”

“I mostly do deliveries. Ma’s training me for the shop, but math really isn’t my thing. That's actually how I befriended your brother.”

“What?”

“I asked him for tutoring.” She smiled. “To help me understand the economics.”

“Huh.” Tsukishima kept his eyes on the road.

The train ride was silent as the car ride.

“Here we go.” She smiled as they got up to the museum.

“Wha-”

“They’re having a special exhibit on dinosaurs. Aki says you like ‘em and… well I don’t know a lot about the dino’s but i’m always willing to learn.” She clapped him on the back. “And I found this great diner close to here. So you wanna eat now or later.”

“I’m… kinda hungry.” He admitted.

“Then let's go!” She grabbed his sleeve and pulled him down the street.

“Here we go!” They stopped in front of the diner. “Best burgers you can get.”

“Mmm.”

“And their specialty is strawberry desserts.” She eyed him, content filling her when she saw him smile.

Lunch was fun. They shared stories about Akiteru and Ryuu and Tsukishima drank two strawberry milkshakes, a slice of strawberry pie, and two slices of the strawberry cake, all while eyeing her chocolate strawberry milkshake.

Then they went to the museum.

And Saeko saw a wide, true smile. There was something about the piles of bones that made that boy shine.

“So what about this one?” She pointed to the dinosaur in front of her.

And off he went. They stood in front of the dinosaur as Tsukishima told her everything he knew about it. Its name, its scientific classifications, what it ate, when it lived, how it would move, what it would be eaten by.

“So what’s your favorite dinosaur?”

“It’s lame, but the Brontosaurus.” He smiled. “There’s just… something about it, I guess.”

She nodded. “Do you mind if we go to the sea life exhibit?”

“You like sea life?”

“Jellyfish, mainly.” She laughed.

“Mmm.”

They moved on to the next dinosaur and she let the matter drop.

“Hey, Tsuki Junior.”

He sighed, not mentioning the nickname. “What.”

“Can I leave you here for five minutes?”

“Sure.” He nodded, staring at the t-rex.

He didn’t even notice that she was gone until she was back and shoving a plastic bag in his hands.

“What’s this?”

“A gift.”

He opened the bag, and then looked at her. “What?”

“It’s… it reminded me of you.”

...0...0...0...

“What did you do with Sae today?” Akiteru looked into Kei’s bedroom.

“Went to the museum.” He nodded. “Saw the dinosaurs.”

Akiteru smiled. “That means you went to the strawberry diner.”

“Mm.”

Akiteru looked around the room and nodded when he saw the new dinosaur on his little brother’s bed. “Nice Brontosaurus.”

“Thanks.”

“With the glasses, it looks like you.”

Kei glared and threw a pillow at him.

Akiteru just laughed and left his brother alone.

* * *

 


	4. The Deal

* * *

 

“So.” Tanaka pulled Tsukishima aside during the lunch break.

“So.”

“Secretly okay?”

Tsukishima nodded.

“Here.” Tanaka handed Tsukishima a piece of paper. “My number. If and ONLY if, our siblings are having sex at your house and you want out or an equally important emergency.”

“Deal.” Tsukishima shoved the paper into his pocket.

  
  
  
  


“Hey, Tsukishima!” Suga smiled.

“Suga.”

“Are you and Tanaka okay now?”

Tsukishima glared across the gym.

“Tanaka, are you okay with Tsuki now?” Suga called across the gym.

They were both silent.

“No?” Suga’s shoulders sagged.

“I don’t want dinosaur breath to contaminate me with his wet blanket-ness.” Tanaka smirked.

“And I don’t want to be contaminated with the stupidity of baldy.” Tsukishima deadpanned.

Suga just sighed.

* * *

 

  


“Hey, Suga.” Yamaguchi whispered after practice.

“Yeah?” Suga whispered back.

“Tanaka gave Tsuki his phone number and Akiteru said that Tsuki likes Tanaka’s older sister.”

“Why those little…” Suga growled. “Imma kill them.”


End file.
